1. Field of the Invention
The present invention relates to an expansion apparatus adapted to be connected to a portable electronic apparatus, such as a laptop personal computer, word processor, etc., to expand the functions of the device.
2. Description of the Related Art
Nowadays, portable electronic apparatus, such as laptop personal computers and book-type personal computers, are widely used due to some advantages including easy transportation, effective use of space, etc.
These conventional electronic apparatuses, however, have only the minimum functions for essential operations. If other functions are required in addition to those basic ones, therefore, the electronic apparatuses conventionally are connected with expansion apparatuses having the additional functions, e.g., a printer, external floppy disk drive unit, etc., by means of connecting cables or the like.
Examples of the expansion apparatuses of this type are disclosed in U.S. Pat. Nos. 4,788,658 and 4,769,764. These apparatuses are of a container type such that a portable electronic apparatus is housed therein while it is operated. Disclosed in Published Examined Japanese Utility Model Application No. 53-29057, moreover, is a connection-type expansion apparatus which is adapted to be connected to the back of a portable electronic apparatus.
The container-type expanding apparatus has a holding recess in which the portable electronic apparatus is to be contained. The electronic apparatus is connected electrically and mechanically to the expansion apparatus in a manner such that the front end of the former is flush with the front edge of the latter. According to this arrangement, moreover, the electrical and mechanical connections between the two systems can be easily achieved by only mounting the electronic apparatus in the holding recess.
However, the electronic apparatus is fixed mechanically to the expansion apparatus with respect to the longitudinal direction only by connecting the respective connectors of the units. If the electronic apparatus is subjected to any external force, therefore, it is very likely to be disengaged from the expansion apparatus. If the electronic apparatus is unexpectedly disconnected from the expansion apparatus during operation, these systems suffer action errors, which result in destruction of in-process data or troubles of the systems themselves. The removal of the mechanical and electrical connections between the electronic apparatus and the expansion apparatus may possibly be prevented by strengthening the connection between their connectors. If this is done, however, it requires troublesome work to disengage the electronic apparatus from the expansion apparatus after use. Since the expansion apparatus of this type is arranged so that the whole electronic apparatus is contained in the holding recess, moreover, it is relatively large-sized and requires a wide installation space.
On the other hand, the connection-type expansion expanding apparatus comprises guide pins to be inserted into guide holes of an electronic apparatus and a screwing mechanism for connecting the apparatus to the electronic apparatus. In connecting this expansion apparatus to the electronic apparatus, the former is first positioned with respect to the rear side of the latter so that the guide pins are aligned with the guide holes. In this state, the expansion apparatus is moved toward the electronic apparatus in a manner such that the guide pins are inserted into the guide holes, and the two units are connected mechanically to each other by means of screws. After the mechanical connection is finished, the connector of the expansion apparatus is connected to that of the electronic apparatus, so that the two systems are connected electrically to each other.
Since the expansion apparatus of this type is connected mechanically to the electronic apparatus by means of the screws, the mechanical connection can hardly be removed by accident during operation. In comparison with the container-type apparatus, however, the connection-type apparatus has a more complicated structure for connection. In making the mechanical connection, moreover, the guide pins must be aligned with the guide holes of the electronic apparatus, thus requiring complicated work. Further, the use of the screws makes the connection and disconnection more troublesome.